Avoid On-Site Headaches Using a Door Spec Checklist
Ordering trade doors online has become normal for installers, contractors, and small developers. It is quick, it suits fast project timelines, and you can line up doors to arrive just when you need them. But if the spec is even slightly wrong, that speed quickly turns into stress.
Small mistakes on a door order can cause big problems on site. A wrong handing, the wrong threshold type, or a missed fire rating can lead to failed inspections, reordering, or awkward workarounds when you are already tight on time and weather. No one wants to be trimming screeds or explaining to building control why a flat entrance door is not fire rated.
A simple, structured checklist keeps everything on track. When you know what to confirm before you order doors online, every made-to-measure uPVC or aluminium door is far more likely to arrive ready to fit, first time. At Trade Window Warehouse, we work with trade customers across the UK, so we see the same spec issues pop up again and again. This guide runs through the main checks on fire ratings, thresholds, handing, hardware, glazing safety and measuring, using UK regulations and real-world site habits as the backbone.
Fire Ratings and Regulations You Cannot Ignore
Fire doors are not just another option on a drop-down menu; they are a life-safety product with strict rules. You need a fire-rated door where regulations call for a protected route, separation or compartment.
Common locations where a fire-rated door is often needed include:
- Flat or apartment entrance doors off shared corridors
- Internal doors onto protected staircases or escape routes
- Doors between an integral garage and the main house
- Certain commercial stair cores, corridors and plant rooms
You will see terms like FD30 or FD60. FD30 usually means a door that can resist fire for 30 minutes, FD60 for 60 minutes. You may also see EI ratings on some technical documents, which relate to integrity and insulation. The key point is to match what building control or the designer has specified.
It also helps to know the difference between:
- Fire door leaf: the door slab itself
- Fire door set: door leaf plus frame, seals, glazing and hardware as a tested package
A fire door only performs as tested when the full door set is kept together. That means:
- The frame profile must match the certification
- The glazing type and layout must match the tested design
- Hinges, closers, locks and latches must be compatible fire-rated items
- Intumescent strips and smoke seals must be the correct size and position
When you order doors online, the safest route is to stay within the manufacturer's certified configurations. Changing the glass type, adding different hinges or trimming too much off the bottom can all affect fire performance and may invalidate any test evidence.
On completion, building control or the client may ask for:
- Third-party certification or product data sheets
- Test reports or assessment summaries
- Permanent labels or plugs on the door or frame showing the fire rating
If you are unsure, check the fire rating, location and documentation needs before you finalise the order.
Thresholds, Access and Weather Performance
Threshold choice is where comfort, access and weather all meet. It is also an area where small misunderstandings can cause big snagging lists.
You will typically choose between:
- Standard raised thresholds for strong weather performance
- Low thresholds for easier step-free access
- Part M style mobility thresholds for dwellings and public buildings
For exposed external doors, especially in harsh UK rain and wind, a higher, more weathered threshold usually gives better protection against water ingress. For balcony and terrace doors, you may be trying to balance drainage with a neat, low step to the outside. Side and rear doors on houses often need to match floor finishes inside while still sealing well.
Main commercial entrances or accessible routes must often meet Part M or similar access requirements. That usually means:
- Minimal upstands or steps at the threshold
- Smooth transitions for wheelchairs and pushchairs
- Careful planning of internal and external floor build-ups
Common mistakes when people order doors online include:
- Forgetting tile thickness or underfloor heating screeds
- Ignoring external paving levels and drainage falls
- Choosing a standard threshold where access rules expect a low or mobility type
Seasonal weather is another factor. For autumn and winter installs, it pays to think about:
- Higher performance external thresholds in exposed locations
- Adequate drainage in front of doors, especially patio and terrace sets
- Cills sized to throw water clear of the wall face
Confirming levels and finishes with the wider project team before ordering takes far less time than sorting out leaks or trip hazards later.
Handing, Swing Direction, Hinges and Locks
Handing and swing direction cause a lot of confusion, especially when different suppliers use different terms. One simple way to stay consistent is to always stand on the hinge side of the door. If the hinges are on your right, it is a right-hand door. If they are on your left, it is a left-hand door. Then confirm whether the door opens towards you or away from you.
Think about:
- Internal vs external doors, including which side needs the more secure hardware
- Push side vs pull side in corridors and small rooms
- Obstructions such as radiators, cupboards and walls
Hardware planning is just as important when you order doors online. You may need:
- Positions and types of hinges, including heavy-duty options for larger sashes
- Multi-point locks with matching keeps and striker plates
- Anti-snap or security cylinders where required
- Handles designed for the weight and use of the door
For security, you may be asked to provide doors that meet PAS 24 or that support Secured by Design specifications. That usually affects:
- Locking systems and keeps
- Cylinder type and resistance
- Glazing choice and bead positions
On escape routes, fire exit doors need the correct panic or emergency exit hardware so people can get out quickly and safely, even in low visibility and high stress. Mixing and matching hardware from different sources on a fire door or heavy aluminium set is risky. It can reduce performance, affect durability, and may break any fire or security certification.
Glazing Safety and Measuring Tolerances That Work
Safety glazing rules in the UK focus on what are called critical locations. These are areas where glass is more likely to be hit or fallen into.
Common critical locations include:
- Any glazing within 800 mm of floor level
- Glazing within 300 mm of the edge of a door and up to 1500 mm high
- Glazed doors from floor level up to at least shoulder height
In these zones, toughened or laminated safety glass is usually required. For trade buyers, the main choices are:
- Toughened glass for impact safety and general use
- Laminated glass where extra security is needed
- Acoustic glass in noisy locations, such as near busy roads or schools
- Obscure or satin glass for bathrooms and privacy-sensitive areas
Measuring is where a lot of jobs win or lose time. Take your measurements from the structural opening, not from old frames that are being removed. Measure the:
- Width in three places, top, middle and bottom
- Height in three places, left, centre and right
Use the smallest measurement each way, then allow for fitting clearance. This gives room for packers and sealant joints. Typical clearances for uPVC and aluminium frames are small but important. If you order a frame too tight, you can end up:
- Forcing it in and distorting the frame
- Creating binding sashes or stiff locking points
- Reducing the effectiveness of weather seals
If in doubt, check what clearance the door supplier recommends and keep that allowance in your final ordered size.
Turn Your Spec Into a Ready-to-Fit Online Door Order
Once you understand the main spec points, you can turn them into a simple checklist for every project. Before you order doors online, confirm:
- Fire rating and door use: is a fire door set needed, and what evidence will be requested?
- Threshold type: standard, low or mobility-friendly, matched to access rules and floor build-ups.
- Handing and swing: checked on the hinge side so it matches the room layout and escape routes.
- Hardware and security level: locks, cylinders, hinges, handles and any PAS 24 or similar needs.
- Glazing: safety glass in critical areas, plus any security, acoustic or privacy requirements.
- Sizes and tolerances: structural opening measured carefully, with the correct fitting clearance allowed.
By having these points ready before you start the quoting process with Trade Window Warehouse, you give every made-to-measure uPVC or aluminium door the best chance of arriving right first time. That means fewer site delays, smoother sign-off with building control, and a more predictable installation programme, especially when projects are under pressure from changeable UK weather.
Get Started With Your Project Today
Transform your home with quality doors tailored to your exact measurements from Trade Window Warehouse. You can quickly order doors online, with clear specifications and options that make it simple to get the right fit first time. If you have any questions or would like a bit of guidance before placing your order, just contact us and our team will be happy to help.
